For those who haven’t studied relativity, this thought experiment is great at showing the “Relativity of Simultaneity”.
The only way the doors can shut from the pole vaulter’s reference frame is if they close at different times. The exit door opens and shuts first, before the tip of the pole has gone beyond it (otherwise it would hit the door, obviously), and then later, only once the back end of the pole has cleared the entrance door, does it close.
For those who haven’t studied relativity, this thought experiment is great at showing the “Relativity of Simultaneity”.
The only way the doors can shut from the pole vaulter’s reference frame is if they close at different times. The exit door opens and shuts first, before the tip of the pole has gone beyond it (otherwise it would hit the door, obviously), and then later, only once the back end of the pole has cleared the entrance door, does it close.